Disease-identifying proteins, toxins and carcinogens, bacteria, viruses, cancerous cells, and many other biomarkers can all be found in the circulatory system, making the blood and other bodily fluids a diagnostic goldmine. The CDC estimates that approximately 6.8 billion in vitro laboratory tests are performed annually in the U.S., making them the most commonly performed medical tests. Conversely, 87% of tests must be sent to a centralized hospital or independent laboratory and generally require hours or even days for results due to sample preparation, assay design, and/or logistic delays. Currently most diagnostic assays require complex sample preparation and are sent to central laboratories that require hours or days for results due to sample preparation, assay design, and logistic delays. Separation of small biomarkers from cellular components in biological fluids is specifically critical for accuracy in diagnostic testing as cellular fractions can cause errors and inconsistencies. Poor sample preparation leads to required reprocessing of samples and the subsequent delays lead to poor patient triage in a hospital setting, which in turn can have life-threatening consequences and this type of separation is not convenient in the field or for remote sensing.
Moving towards a lab-on-a-chip system for diagnostic testing offers many advantages such as automated measurement, low sample and reagent volumes, minimal sample preparation, portability, disposability, and user-friendly interfaces. An automated lab-on-a-chip filtration device could help eliminate laboratory delays and results could be analyzed more quickly in the field/at the patient's side and without the risk of human error. Thus, development of a portable, robust, disposable biological fluid separation chip could significantly enhance the realization of a number of developing point-of-care devices with a variety of applications such as remote and emergency health monitoring, pharmaceutical testing, academic research or home test kits.
Lab-on-a-chip type sensors utilizing disposable chip platforms are emerging as a promising technology for detecting and monitoring biomarkers and environmental agents in the blood, urine, saliva, drinking water, and consumable products. A couple systems have been implemented for the most frequently ordered blood tests such as: monitoring electrolytes, metabolites, blood gases, and hematocrits (I-STAT); to detect HIV, syphilis and other infectious diseases (mChip); and to perform up to 25 routine check-up blood panels with one device by combining optical light scatter, colorimetric and electrochemical methods (Ativa). However a number of setbacks arise when designing sensing platforms for detecting more complex or newly emerging biomarkers. This is especially true for small molecules with structures such as foreign toxins, carcinogens, and drugs with low immunogenicity. We aim to solve this by combining our group's assays, which have demonstrated the ability to overcome this issue in the utilization of engineered sensing ligands and signal enhancing nanoparticles for ultra-low limits of detection, with custom optofluidic chips to portably house the assay and provide user-free sample preparation.
Sensing assays discussed herein are easily translatable to virtually any biomarker through the utilization of engineered sensing ligands and signal enhancing nanoparticles for ultra-low limits of detection, with custom optofluidic chips to portably house the assay and provide user-free sample preparation. This technology can potentially be made robust, field portable, and sensitive to other analytes by changing the biorecognition molecule and aptamer—making the platform ‘programmable’. Thus the chip platform can potentially be used for a number of applications in situations where rapid blood or other biofluid diagnostics are of critical necessity, such as, for example, for biomarkers for preeclampsia, dengue fever, radiation exposure, blood toxins, or myocardial infarction. Its versatility, low manufacturing cost, and portability also make it a promising technology for global health implications, ambulatory settings, as well as natural disaster relief worldwide. The enablement of technologies like this help push medicine to become increasingly personalized, predictive, and preventative by moving away from initial symptom based diagnostics and towards fast, quantifiable monitoring.